The present invention relates to a pain alleviating and tissue treatment assembly, and in particular, to a cold electrode assembly to alleviate pain and discomfort and accelerate healing in an transcutaneous electro neural stimulation process by reducing the temperature of the body tissues in contact with the cold current application electrode. This invention is also applicable to neuro surgery where small temperature controlled electrodes are implanted.
The nerves in the human body are associated with chemicals which combine and react according to an applied stimuli. Dependent upon this stimuli, a reaction results causing an electrical shift of the polarization of the neuron, or nerve, which then is transmitted as a pain signal or appropriate sensation. Because this reaction is basically chemical in nature, the reaction follows and obeys the general rule for stimuli activated reactions, and the reaction rate doubles for each 10.degree. C. temperature increase. This acceptable principle has been used for years by surgeons and technicians in the medical profession by applying local anesthesia for minor surgery. Typically, compressed liquids such as ethyl chloride are sprayed directly on the tissue surrounding or involved in the surgical site. A substantial cooling of the tissue can result in an accompanying anesthetic effect. Some disadvantages are associated with this basic technique, including the requirement for the operator periodically to stop the treatment, and to recool the tissue surrounding the treatment site. Prior art patents include my own issued U.S. Pat. No. 4,646,735 for the PAIN ALLEVIATING TISSUE TREATMENT ASSEMBLY wherein a surgical site and the operating instrument are concurrently cooled to a substantially reduced temperature, using cold, dry, sterilized air gases or other treatment fluid. This assembly uses a liquid refrigerant and fluid system in combination with a microrefrigerating vaporator built into the handpiece, bringing cooling fluid to the working tip of the instrument and the site where the instrument is to be used.
The Deutsch U.S. Pat. No. 5,097,828 is a thermoelectrotherapy device using a heat sink for dissipating heat generated by Peltier effect devices. A contact plate is connected to a high voltage source to provide electrical stimulation to the skin and underlying tissue while applying the cold to the surface.
The Perler U.S. Pat. No. 4,614,191 discloses a skin cooling probe which anesthetizes, or desensitizes, a skin target area prior to removal of hairs by electrolysis. The cycle is limited to three seconds of cooldown followed by a twenty-five second heat sink cooling period, with this cycle repeated.
The Wong et al. U.S. Pat. No. 4,848,357, Morez U.S. Pat. No. 4,895,149, Rossen U.S. Pat. No. 4,989,605 and Slovak U.S. Pat. No. 5,058,605 are cited as being of general interest and relate to various non-invasive nerve stimulation devices in alleviating pain and treatment using an electrical energy system.
Other therapeutic devices of interest are shown in Tateisi U.S. Pat. No. 3,207,159, Kissen U.S. Pat. No. 4,585,002, Ghiurco et al. U.S. Pat. No. 4,860,748, Eidus U.S. Pat. No. 3,133,539, Okuhara U.S. Pat. No. 3,168,895, Ruderin U.S. Pat. No. 4,640,284 and Son U.S. Pat. No. 4,915,108. Patents for reducing the temperature of surgical instruments during the performance of surgical techniques are shown in Reynolds U.S. Pat. No. 3,548,829, Peters U.S. Pat. No. 3,494,364, Hershorn U.S. Pat. No. RE 26,276, Gregory U.S. Pat. No. 4,367,743, Kandbar U.S. Pat. No. 3,259,131, Zobac U.S. Pat. No. 4,345,598, Koloner U.S. Pat. No. 3,794,039 and Lloyd U.S. Pat. No. 4,207,897, among others.
Normal functioning of nerve and other body cells and tissue requires a very exact biochemical and biophysical composition and construct. The nervous system requirements are such that polarized electrical communication is almost instantly available from sensory to central decision making areas to motor and organ systems. Accidents, trauma, and disease processes frequently result in forces that apply stresses to individual nerve cells and aggregates, or bundles, of nerve cells and their parts. These stresses may cause ongoing, if not permanent, displacement of the nerve cells, their parts, and the biochemical components within and surrounding them. In some cases, the polarity of nerve fibers may be reversed, or perhaps merely reduced or neutralized. The unnatural conditions of polarity may alter the normal operation of the ion regulating channel in the presynaptic vesicles of a nerve transmitter mechanism, blocking the flow of sensory impulses to the sensory nervous system where decisions are made. They may occur in strategically placed locations that interfere with decision making or intelligence, or they may occur in areas that block motor messages being sent by the central nervous system to the end organs by way of the motor division of the nervous system.
In any of these situations, normal function of the total nervous system, and thus of the owner/vehicle of that nervous system is impaired. The impairment may manifest itself in the loss of sensation, such as pain, heat, cold and so forth. It may manifest itself as the inability to decide what to do or how to do it, as in some form of aplasia. It may show itself as an inability to move a body part, even though one knows precisely what one wants to do. It may mean that one loses an involuntary function, such as bladder control or the like.
One reason for reversed polarity is a forced transition of the biochemical organization of nerve cell composition where intracellular sodium, potassium and calcium ion control and generating sites are located. The function of these ion generating sites may be reversed or maladjusted. Nerve cells may be considered analogous to a pulse generating battery that has two plates with an electrolyte therebetween. The electrolyte has the ability to change ionic composition very rapidly in response to the activity at the plates. In this model, an overload or mechanical deviation might cause a positive cellular electrode or plate to become negative and/or a negative electrode or plate would become positive. If both plates or electrodes become the same polarity at the same time, no electrical pulse will be generated, and therefore it will not be recognizable or usable within the system. In this case, it would not be usable within the nervous system.
In many cases, scientifically manipulated mechanical and biogenerated electrical forces can be used to directly repolarize and/or urge disoriented nerves to become properly polarized. Even in cases where severe disorientation has occurred, the healing process can be significantly accelerated by including engineered electrophoric technology in the treatment process. This is done with transcutaneous electrical nerve stimulation devices, which are well known in the prior art.
This invention is capable of providing for the neurosurgeon small implantable electrodes that can be placed adjacent to or in the vicinity of damaged nerves or muscles. Small currents are applied in different selectable treatment modes while the electrode (positive or negative or both) is held at a substantially constant cold temperature.